Gas-blast circuit breaker



March 13,l 1931.1.

s. RUPPEL l GAS BLAST CIRCUIT BREAKER Filed July 8. 1931 5 Shets-Sheet l Inventor: Sgwart Ruppel,

Hts Attorney.

Inventor` lil..

S. RUPPEL Filed July 8, 1931 ww p w u n R w O .U TY W m E .m s

GAS BLAST CIRCUIT BREAKER March 13, 1934.

March 13, 1934. s. RUPPEL GAs BLAsT CIRCUIT BREAKER Filed July 8. 1931 3 Sheets-Sheet 3 lm/entor: Slgwart Ruppel, bfU Mmm l-iis AttovnQg.

Patented Mar. 13, 1934 UNITED STATES PATENT OFFICE GAS -BLAST CIRCUIT BREAKER Application July 8, 1931; Serial No. 549,466 In Germany August 30, 1930 6 Claims. (Cl. 200-148) My invention relates to gas-blast circuit breakers, more particularly to circuit breakers of the aforesaid type wherein a blast of gas at high velocity is directed across the arc gap G formed upon separation of the contacts and through one of said contacts comprising the exhaust passage for the blast.

It is a principal object of my invention to provide an improved circuit breaker of the gas- 10 blast type which shall be simple and rugged in construction, of comparatively few parts and which shall have a substantially uniform and unobstructed gas passage for directing gas at high and effective velocity through the arc gas 16 upon separation of the contacts.

In accordance with my invention, the gas under pressure is supplied to the circuit breaker through a conduit or the like, which is in communication and coextensive with a hollow tubu- 20 lar contact substantially uniform in cross section with respect to the cross section of the supply conduit. The aforesaid tubular contact terminates in a contacting portion coacting with a hollow nozzle-like contact comprising the exhaust passage of the gas directed across the arc gap upon separation of the contacts. By reason of the substantially uniform gas passage leading from the source of pressure to the point of separation of the contacts, dead spaces within the gas line and switch casing are eliminated thereby precluding excessive expansion of the gas andconsequent drop in pressure within the gas line. Accordingly, maximum pressure is available at Vthe switch contacts to cause the arc extinguishing gas blast. Likewise, due to the fixed relation between the tubular contact forming part of the gas line and the contact portion carried thereby, the design may readily be such that the contact portion is subjected to the most effective blast during the entire switch opening movement.

My invention will be more fully set forth in the following description referring to the accompanying drawings, and the features of 15 novelty which characterize my invention will be pointed out with particularity in the claims annexed to and forming a part of this specification.

Referring to the drawings, Fig. 1 is an elevational view, partly in section, of one form of a gas-blast circuit breaker embodying my invention; Figs. 2 and 3 are similar views showing other forms; Fig. 4 is an elevational View, shown F partly and in section, of a modified form of that "5 shown in Fig. 3; Figs. 5, 6, 7 and 8 are similar views of .other forms o circuit breakers embodying my invention; Fig. 9 is an elevational View, partly in section, of a double pole gasblast circuit breaker; Fig. l0 is an elevational View, partly in section, showing a main and auxiliary switch arrangement; Fig. 11 is a similar view of another form my invention may assume; Fig. 12 isa fragmentary view, partly in'section, of a modified form of that shown in Fig. 11, and Figs. 13 and 14 are elevational 6l views, partly in section, showing circuit breaker structure.

In the circuit breaker illustrated in Fig. 1 the contacts between which the gas blast is directed comprise a stationary hollow nozzle-like con- I0 tact l formed of suitable conducting material and a relatively movable contact portion or pin 2 mounted, as by the ribs 3, at the upper open end of the tubular contact member 4 likewise formed of conducting material. The tubular contact 4 forms part of the gas line to the point of separation of the switch contacts. To this end it communicates and is coextensive with the gas supply conduit or tube 5 which is mounted on the movable frame 6 and arranged 00 at its lower end for connection to a suitable source of gas pressure, as compressor tanks, carbon dioxide asks, or the like.

The length and position of the contact pin 2 with respect to the exhaust end of the tubular S5 member 4 is preferably such that the pin is subjected to the most effective gas ow and velocity from the tubular member 4 for extinguishing the arc. Since this relationship is not changed by separation of the contacts it may be permanently established in the initial design of the circuit'breaker. Accordingly, it will be seen that the pin 2 is subjected to substantially uniform gas velocity and is within the most favorable gas blast during the switch opening movement.

The`circuit breaker casing or housing comprises in the present instance a hollow insulating sleeve or bushing l suitably mounted, as by bracket structure 8, at the upper part of the l frame 6, the insulating bushing 7 being of any suitable insulating material as porcelain, resinous impregnated laminated structure, or the like. The longitudinal bore '7' formed within the insulator 7 receives at its lower end the gas supl ply conduit 5 over which is tted in telescopic relation the movable tubular contact 4. The contact 4 is therefore guided for reciprocal movement with respect to the contact 1 by the conduit 5 and is operatively connected through a n.

crank 10 to the actuating cylinder 9. An offset insulating link indicated at 11 connects the actuating arm of the crank to the hollow contact 4 as by an oiset pin 12. l

At the upper end of the bore '7' the nozzle-A like contact 1 is mounted on the insulator 7, the arrangement being such that gas may be directed at high velocity through the supply conduit 5, tubular contact 4, and across the arc gap formed upon separation of the contacts 1 and 2v in response to opening of the circuit breaker by counterclockwise rotation of the crank 10. Since the ribs 3 supporting the contact portion 2 are then and oier comparatively small resistance to gas iiow, it will be apparent that the gas blast in effecting interruption of the circuit is directed through a substantially uniform and unobstructed gas passage so that the maximum available gas pressure is utilized in extinguishing arcing.

The circuit breaker terminal for the movable contact may comprise any suitable arrangement for making contact with the same, and in the present instance the telescopic contact member 4 is in sliding conducting relation to flexible conducting fingers or the like 13 suitably mounted on the terminal cap le secured to the lower end of the bushing 7.

In the arrangement illustrated in Fig. 2 the nozzle-like contact 1 is carried by the insulators 15 mounted on the upper part of the movable frame 6, the movable contact portion 2 being carried in a manner similar to that described above by the ribs 3 mounted in the open upper end of the movable tubular contact ln this arrangement the stationary gas supply conduit 5 is supported by an insulator 16 suitably mounted on the frame 6 and is continuous with a bore 17 extending through the insulator communicating with a source of gas pressure indicated at 18. The tubular contact 4 is, as in the previous instance, slidably mounted in telescopic relation to the gas supply conduit 5, the contact 4 being electrically connected to the conducting terminal cap 19 as by flexible leads 20 partly enclosed by a cylindrical shield 21.

The contact chamber of the circuit breaker is formed by a cylindrical insulating member 22 depending from the stationary contact l and open at its lower end through which the tubular contact i extends. For the purpose of making a sealing t between thel Contact l and the insulating cylinder 22 during the gas blast and for accelerating the switch opening movement in a manner hereinafter described there is provided an insulating sleeve 23 mounted on and carried by the upper portion of the contact Il. When the circuit breaker is opened in response to clockwise rotation of the actuating arm 24 which is suitably connected, as by the insulating link 25, to the contact 4, coincident with admission of gas under pressure to the gas supply line, it will be apparent that the gas acts on the insulating member 23 as on a piston to accelerate the downward or switch opening movement, the gas meanwhile exhausting at high velocity through the nozzle contact 1 to extinguish the. arc. l

In this, as in the previous instance, the gas is directed to thefpoint of separation of the contacts through a substantially uniform gas path, the small space within the cylinder 22 bem ing immediately adjacent the arc gap so that no appreciable reduction in gas pressure is ene countered. For the purpose of preventing eddies in the gas current the insulating member may extend somewhat above the open end of the tubular contact and is suitably shaped for presenting minimum resistance to gas ow.

When the circuit breaker is in the open position the member 23 is below and without the cylinder 22 so that free circulation of air through the contact chamber is permitted, thereby minimizing formation of moisture and deposits of conducting or other material therein. It will be likewise noted that the insulating member 23 aiords a visible indication of the open circuit position of the switch, the member 23 in the closed circuit position being within and concealed by the insulating cylinder 22.

Fig. 3 shows` the circuit breaker mounted on a stationary frame 9, the contact chamber in the present instance being formed by an insulating shell 26 supported by the frame 9. The shell 26 has mounted at its upper end the stationary nozzle contact 1, the movable contact portion 2 being connected to the upper open end of the movable tubular contact 4 by the ribs 3 and extending through the insulating shell to engage the contact 1. As in Fig. 2, the tubular contact 4 is provided with an insulating member 23 functioning to seal the contact chamber during normal operation and to .accelerate the switch opening movement. The terminal structure connected to the movable contact ll comprises a flexible conductor 27 mounted. within a protecting tube 23 which is pivotally mounted at one end on the insulating support 29 and slidably connected, as by pin and slot connection generally indicated at 30, to the contact 4. The conductor 28 is suitably connected at one end to the contact 4 and at its other end to a terminal lug 31 carried by the insulator 29.

In other respects the construction shown in Fig. 3 is generally similar to that described in connection with Fig. 2, the actuating arm 24 and connecting link 25 causing opening and closing movement of the tubular contact l which slide.;y over and is guided by the gas supply conduit 5 connected to the source of pressure 18. The method of operation is likewise similar to that of the circuit breaker shown in Fig. 2.

Fig. 4 shows a wall-mounted circuit breaker supported by suitable bracket structure 32. In this arrangement the contacts and contact chamber are substantially identical to that illustrated in Fig. 3, the insulating shell 26 being supported by a 'clamping ring or the like 33 comprising part of the supporting bracket. For the purpose of eliminating iiexible conductors, the gas supply conduit 5 is composed of conducting material with respect to which the movable tubular contact l is in Sliding conductn ing engagement by means of spring pressed seg*n ments 34. The segments 34 may be suitably carried by the contact e and resiliently biased into conducting engagement'with the conduit 5, as by garter springs 35 or the like. The lower part of the conduit 5 may be suitably connected to the terminal lug 35 so that the current flows in a substantially straight line through, the circuit breaker, thereby eliminating certain stresses due to magnetic forces.

The actuating arm 2li is operatively connected to the tubular contact Ll described and the gas distributing pipe or source of pressure i8 likewise is connectedto the duit 5 in a similar manner. With t .lis C4nge ment the supporting bracket 32 may be secured to a wall `so that the circuit breaker and live in a manner previously i parts of the circuit are separated from the actuating mechanism and the switch attendants by the wall.

For the purpose of absorbing and dissipating impact forces due to operation of the circuit breaker, the nozzle contact may be provided with a resilient mounting permitting limited movement thereof. Such an arrangement is shown in Fig. 5, the circuit breaker in general being similar to that described in connection with Fig. 4. In Fig. 5 the nozzle contact 1 is slidably mounted within the supporting ring 37 and is provided with a cylindrical extension 38 between which and the ring 37 a `compression spring- 39 is positioned. 'The spring 39 is normally under compression so as to maintain the contact 1 in seating engagement with the ring 37. The movable tubular contact 4, to which the contact pin 2 is secured by the ribs 3, is provided with an expanded portion 40 partly taking the place of the insulating seal 23 of the arrangements above described. For the purpose of completing the seal between the tubular contact 4 and the contact chamber formed by the insulating cylinder 4l, an insulating ring 42 formed of felt or the like may be attached to the contact 4.

The circuit through the breaker includes the sliding conducting segments 3'5 connecting the tubular contact 4 to the gas supply conduit 5 in the manner shown in Fig. 4, the remaining features of operation and construction being substantially the same.

Fig. 6 shows a wall-mounted arrangement comprising a bracket supporting structure 43 on which is mounted a hollow insulating bushing 44 carrying at its upper end the xed nozzle contact l and at its lower end a terminal cap 45 which is in electrical contact with the movable tubular contact 4 by means of the conductor segments 46 spring biased, in the manner previously described, into conducting engagement with the sliding contact 4. An insulating guiding sleeve 44 is mounted within the insulator 44 sealing the tubular contact 4 and guiding the same for reciprocal movement. In this case the terminals of the circuit breaker are carried by the opposite ends -of the insulator 44 as in Fig. l so that the gas supply conduit 5, over which the tubular contact 4 slides in a telescopic manner, may be composed of any suitable material.

The tubular contact 4 is operatively connected to the actuating arm 47 by a link 48 which in turn is pivotally connected, as at 49, to offset extensions 50 of the contact 4. ln the case oi a polyphase arrangement a transversely extending insulating member. 51 secured to the contact 4 causes simultaneous operation of the other phase breakers. This arrangement applied to polyphase breakers is further shown in Fig. 7, the offset portion 50 being connected to the transverse insulating member 5l in the manner above described.

The arrangement shown in Fig. 8 is generally similar to that of Fig. 2 with respect to the contact structure, the contact chamber being formed by an insulating shell 53 mounted on the frame 54 and supporting in turn at its upper end the stationary nozzle contact 1. A terminal cap 55 to which the Contact 1 is suitably secured supports in depending relation within the insulating shell 53 an insulating cylinder 56 within which the movable tubular contact 4 extends. The insulating cylinder 56, which may be appreciably smaller in diameter than the supporting insulating shell 53, therefore maintains the cross section of the gas line substantially uniform. The insulating seal 23, as in Fig. 2, is suitably shaped so as to present minimum resistance to gas flow.

4The tubular contact 4 is in conducting relation to the gas supply conduit 5 by means of the conducting segments 57 carried by the tubular contact 4 as in Fig. 4. The conduit 5, which is of conducting material, is suitably connected to the terminal cap 58, the operation of the breaker and connection between polyphase units being substantially the same as that of Fig. 6, the actuating arm 47 and link 48 being operatively connected to the transverse insulating ba'r 51 to cause simultaneous operation of the polyphase units.

-In Fig. 9 a ydouble pole circuit breaker is shown, the contact structure and switch casings of the individual poles being substantially the same as that in Fig. 3, the corresponding parts in Fig. 9 being designated by the same reference characters. The insulating shells 26 forming the switch chambers of the two poles respectively are suitably mounted on the ,movable frame 59, the movable tubular contacts 4 being connected to form a U-shaped conduit 60 which is connected at its lower mid-point to an insulating tube 6l ior'ming'part of the gas supply line. The tube 61 slides over and is co-extensive with the stationary gas supply conduit 5 which is in communication with a distributing line or source of pressure 18. Since the circuit terminals in the present instance comprise the stationary nozzles 1, no current connections are necessary between the stationary and movable parts of the gas supply line. Accordingly, the live movable partsof the switch may be adequately insulated with respect to the gas conduit 5 by the insulating tube 61 which is likewise surrounded by an insulating shell 62 o ceramic material or the like. The insulating shell 62 is suitably connected to the U-shaped member 60 and is likewise connected to a transverse bar 63 connected to similar phase units and operatively connected to the actuating arm 64 through the link 65. Further description of the stucture or method of operation is believed unnecessary other than to note that the gas supply line leading to the U-shaped member 60 should have substantially twice the cross sectional area of the U-shaped member in order that the volume of gas delivered to the individual poles shall be substantially the same as in a single pole arrangement having a uniform gas line.

Fig. lo illustrates a gas blast circuit breaker, generally similar to that shown in Fig. 6, connected in parallel with an auxiliary or main. current-carrying switch which is arranged to open prior to opening oi the contacts of the gas blast switch. The auxiliary switch comprises an insulating bushing 66 mounted on the supporting bracket 67 which likewise carries the gas blast switch indicated at 68, the insulator 66 having mounted on its upper end the terminal structure and stationary contacts generally indicated at 69 and at its lower end a terminal structure 70 in conducting relation with the movable rod contact 7l. With the auxiliary and gas blast switches in the closed circuit position illustrated, the current is shunted around the gas blast switch by the lower conducting lug 72, terminal structure 70, movable contact rod 7l, and contact and terminal structure 69 which lll@ -connected to the tubular contact 4 so that switch operation thereof is effected by the actuating arm 75. If desired, a blast of gas may also be directed between the contacts of the auxiliary switch during switch opening movement so that the'possibility of reestablishment of the arc at the auxiliary contacts is precluded."

In such an arrangement the contact rod 71 and crossbar 74 might be hollow and communlcating with the conduit 5 for admitting the gas to the auxiliary switch contacts in the manner previously indicated.

In Fig. 11 the relative movement of the tubular and nozzle contacts is accomplished by mounting the nozzle contact 1 for pivotal movement on a crank 76, the tubular contact 4 and contact portion 2 being suitably shaped to correspond to the arcuate movement of the nozzle contact. The contact chamber is formed by a hollow insulating shell 77 within which is mounted an annular insulating ring 78 functioning to seal the contact 4 with respect to the contact chamber during the gas blast in the manner previously indicated. The entire structure including the insulating supporting bushing 16 and the distributing line or source of pressure 18 is suitably mounted upon a frame 79.

Operation of the circuit breaker is effected by an actuating arm 80, connected through a llnk 81 to one arm of the crank 76 which is pivotally mounted as at 82 on an insulator 83 moved into the pipe 84 for carrying away the l nel'.

carried by the frame 79. Upon opening of the breaker in response to clockwise rotation of the arm and crank 76, the nozzle contact 1 is switch exhaust gases, separation of the nozzle contact 1 from the contact portion 2 being accompanied by a gas blast through the supply line including the tubularlcontact 4 in the manner previously described for extinguishing the arcf If desired, the tubular contact 4 instead vof being rigidly mounted on the insulator 16 may be movably mounted as by a ball and socket connection so as freely to move in accordance with the nozzle contact 1. In this arrangement the contact chamber and nozzle contact comprising the movable parts of the switch are preferably of small mass for the purpose of permitting rapid opening movement of the switch.

The arrangement in Fig. 12 is generally similar to that of Fig.`11 except for the fact that the movable nozzle contact 1 is mounted on the links and 86 for substantially rectilinear or straight line movement. An insulating gas exhaust pipe 87 is joined to the nozzle contact 1 and is movable therewith by the links 85 and 86, a stationary exhaust pipe (not shown) receiving the exhaust pipe 87 in a telescopic man- The stationary part of the switch comprises the insulating support 88 on which is mounted the tubular contact 4 and contact pin 2, the gas line extending uniformly throughA the insulator 88 and contact 4 to the point of separation of the contacts 1 and 2. The contact housing is formed by the insulating shell 89 carried by the lower portion of the nozzle contact 1 so that the operation of the circuit breaker is substantially the same as that of Fig. 11. The switch terminal structure comprises a sta- 1,951,210 .is connected to the stationary nozzle contact 1 tionary terminal cap 90 to which the tubular contact 4 is attached, the upper terminal comprising the nozzle contact 1 which is electricallyn connected to the link 85 which serves as the current conductor.

In Figs. 13 and 14 there is disclosed an arrangement particularly suitable for operation of pclyphase units, the single phase gas blast circuit breaker shown in Fig. 13 being generally similar to that of Fig. 4 and designated in the same manner. In the present instance the actuating arm 91 operatively connected to the movable tubular contact`4 is mounted on a rotatable shaft 92 composed of mechanically strong insulating material, the shaft 92 being common to the individual phase units. As best illustrated in Fig. 14, the shaft 92 has mounted thereon a plurality of insulting bushings 93 of ceramic material or the like, the bushings being suitably joined at adjacent ends by flanged coupling members 94. On each bushing 93 is mounted a corresponding switch actuating arm. 91 in the manner indicated in Fig. 13. For the purpose of more eiectively insulating the individualphases of the circuit breaker, each insulator 93 is provided adjacent its opposite ends with skirts or shields 95, thereby lengthening the creepage path betweenphases. The shaft 92 at its actuated end is provided with a coupling 96 secured to the adjoining insulator, the coupling being rotatable within a-bearing 97 and connected to a main driving link 98 for causing rotation of the shaft 92 and the respective phase actuating arms 91. It will, therefore. be noted that the main torsional stress is applied to the actuating arms of the phase units through the' coupling members and insulators 93, the insulating shaft 92 serving mainly to support and insulate the rotating structure. For the purpose of more effectively isolating the actuating mechanism of the diiferent phases the metallic couplings 94 may be suitably grounded.

It shall of course be understood that any of the circuit breakers above described may be suitably arranged for polyphase operation through a common switchdrive. In order to prevent welding or burning of the contacts when the circuit breaker is closed on heavy short circuits a preliminary gas blast may be directed between the contacts, thereby preventing arcing before the contacts are actually in engagement.

It should be understood that my invention is not limited to specific details of construction and arrangement thereof herein illustrated, and that changes and modifications may occur to one skilled in the art without departing from the spirit of my invention.

What I claim as new and desire to secure by Letters Patent of the United States, is,-

1. A gas blast circuit. breaker including a sleeve-like casing and relatively movable contactsVone of said contacts comprising a nozzlelike structure forming the exhaust passage of the gas blast at one end of said casing, the other coacting contact comprising a tubular member operable within said casing and terminating at an open end in a contact pin arranged to engage said nozzle contact, said pin positioned a fixed distance beyond said tubular member and supported thereat by ribs mounted within said open end of the tubular member, said casing and tubular member arranged so that a comparatively small switching chamberv is formed thereby during the initial separation of saidv tubular member for supplying gas from a source of pressure directly `to the point of separation of the contacts, said pin contact bearing a fixed relation to the exhaust opening of said tubular member during the switch opening movement.

2. A gas blast circuit breaker including relatively movable contacts comprising a nozzle contact forming the exhaust of the gas blast and a pin contact engaging and surrounded by said nozzle contact in the closed circuit position, said pin contact carried by a movable tubular member at an open end thereof, and a conduit communicating with a source of pressure and continuous with said tubular member, said tubular member mounted for reciprocal movement in telescopic relation to said conduit.

3. A gas blast circuit breaker comprising a hollow insulating bushing, a nozzle contact mounted at one end of said bushing and a movable tubular contact coacting therewith extending within said bushing through the other end thereof, a conduit communicating with a source of gas pressure, said conduit continuous with and guiding said tubular contact in telescopic relation, and terminal structure mounted on said insulator in sliding conducting engage'- ment with said tubular contact.

4. A gas blast circuit breaker comprising a casing open at one end thereof, a nozzle-like contact mounted at the opposite end, means including a tubular contact member extending within the open end of said casing and engaging said nozzle contact in the closed circuit position, Saidtubular member being in communication with a source of pressure for directing gas to the point of separation of said contacts, and means including a seal between said tubular member and said casing together with said tubular member closing the open end of said casing during interruption of the circuit, said sealing means utilizing the gas pressure to accelerate the switch opening movement.

5. A gas blast circuit breaker comprising relatively movable contacts, a conduit composed of conducting material communicating with a source of gas pressure, said conduit forming a switch terminal, tubular structure comprising one of said contacts mounted in telescopic relation with respect to said conduit and forming therewith a gas passage to the point of separation of said contacts, and conducting means carried by said tubular structure in sliding engagement with said conduit.

6. A gas blast circuit breaker comprising a pair of relatively movable contacts between which gas at high velocity is directed for extinguishing arcing, one of said contacts comprising a nozzle-like structure and the other coacting contact including a pin engaging and surrounded by said nozzle contact in the closed circuit position, and means resiliently mounting said nozzle contact for absorbing. impact forces during operation of the circuit breaker.

SIGWART RUPPEL. 

